Studies on Naturally Occurring and Synthetic Quinones

Many synthetic as well as natural products containing the quinone functionality have displayed useful chemotherapeutic activity. Benzoyl/naphthoyl/thienoyl-1,4-benzoquinones have emerged as potential building blocks for the synthesis of medicinally significant anthracyclinones. Anthracyclinones are valuable drugs in the treatment of certain human cancers. The 1,4-benzoquinones are strong electrophiles in the Diels-Alder reactions with variously substituted 1,3-butadienes. This property of quinones has been of great synthetic value.Encouraged by remarkable achievements in the field of naturally occurring as well as synthetic quinones , a systematic study of quinones including their isolation and synthesis have been undertaken. In the present study isolation of quinones from Tecomellaundulata, synthesis of rhinacanthin-A (a naphthoquinone) from lapachol and a number of benzoyl-1,4-benzoquinones were synthesized which are good precursors for the Diels-Alder reaction with various dienes and therefore, this approach may further be extended to the synthesis of anthracyclinones.